+ be given as <STRONG>smcup</STRONG> and <STRONG>rmcup</STRONG>. This arises, for example, from terminals
+ like the Concept with more than one page of memory. If the terminal
+ has only memory relative cursor addressing and not screen relative
+ cursor addressing, a one screen-sized window must be fixed into the
+ terminal for cursor addressing to work properly. This is also used for
+ the TEKTRONIX 4025, where <STRONG>smcup</STRONG> sets the command character to be the
+ one used by terminfo. If the <STRONG>smcup</STRONG> sequence will not restore the
+ screen after an <STRONG>rmcup</STRONG> sequence is output (to the state prior to
+ outputting <STRONG>rmcup</STRONG>), specify <STRONG>nrrmc</STRONG>.
+
+
+</PRE><H3><a name="h3-Margins">Margins</a></H3><PRE>
+ SVr4 (and X/Open Curses) list several string capabilities for setting
+ margins. Two were intended for use with terminals, and another six
+ were intended for use with printers.
+
+ <STRONG>o</STRONG> The two terminal capabilities assume that the terminal may have the
+ capability of setting the left and/or right margin at the current
+ cursor column position.
+
+ <STRONG>o</STRONG> The printer capabilities assume that the printer may have two types
+ of capability:
+
+ <STRONG>o</STRONG> the ability to set a top and/or bottom margin using the current
+ line position, and
+
+ <STRONG>o</STRONG> parameterized capabilities for setting the top, bottom, left,
+ right margins given the number of rows or columns.
+
+ In practice, the categorization into "terminal" and "printer" is not
+ suitable:
+
+ <STRONG>o</STRONG> The AT&T SVr4 terminal database uses <STRONG>smgl</STRONG> four times, for AT&T
+ hardware.
+
+ Three of the four are printers. They lack the ability to set
+ left/right margins by specifying the column.
+
+ <STRONG>o</STRONG> Other (non-AT&T) terminals may support margins but using different
+ assumptions from AT&T.
+
+ For instance, the DEC VT420 supports left/right margins, but only
+ using a column parameter. As an added complication, the VT420 uses
+ two settings to fully enable left/right margins (left/right margin
+ mode, and origin mode). The former enables the margins, which
+ causes printed text to wrap within margins, but the latter is
+ needed to prevent cursor-addressing outside those margins.
+
+ <STRONG>o</STRONG> Both DEC VT420 left/right margins are set with a single control
+ sequence. If either is omitted, the corresponding margin is set to
+ the left or right edge of the display (rather than leaving the
+ margin unmodified).
+
+ These are the margin-related capabilities:
+
+ <STRONG>Name</STRONG> <STRONG>Description</STRONG>
+ ------------------------------------------------------
+ smgl Set left margin at current column
+ smgr Set right margin at current column
+ smgb Set bottom margin at current line
+ smgt Set top margin at current line
+ smgbp Set bottom margin at line <EM>N</EM>
+ smglp Set left margin at column <EM>N</EM>
+ smgrp Set right margin at column <EM>N</EM>
+ smgtp Set top margin at line <EM>N</EM>
+ smglr Set both left and right margins to <EM>L</EM> and <EM>R</EM>
+ smgtb Set both top and bottom margins to <EM>T</EM> and <EM>B</EM>
+
+ When writing an application that uses these string capabilities, the
+ pairs should be first checked to see if each capability in the pair is
+ set or only one is set:
+
+ <STRONG>o</STRONG> If both <STRONG>smglp</STRONG> and <STRONG>smgrp</STRONG> are set, each is used with a single
+ argument, <EM>N</EM>, that gives the column number of the left and right
+ margin, respectively.
+
+ <STRONG>o</STRONG> If both <STRONG>smgtp</STRONG> and <STRONG>smgbp</STRONG> are set, each is used to set the top and
+ bottom margin, respectively:
+
+ <STRONG>o</STRONG> <STRONG>smgtp</STRONG> is used with a single argument, <EM>N</EM>, the line number of the
+ top margin.
+
+ <STRONG>o</STRONG> <STRONG>smgbp</STRONG> is used with two arguments, <EM>N</EM> and <EM>M</EM>, that give the line
+ number of the bottom margin, the first counting from the top of
+ the page and the second counting from the bottom. This
+ accommodates the two styles of specifying the bottom margin in
+ different manufacturers' printers.
+
+ When designing a terminfo entry for a printer that has a settable
+ bottom margin, only the first or second argument should be used,
+ depending on the printer. When developing an application that uses
+ <STRONG>smgbp</STRONG> to set the bottom margin, both arguments must be given.
+
+ Conversely, when only one capability in the pair is set:
+
+ <STRONG>o</STRONG> If only one of <STRONG>smglp</STRONG> and <STRONG>smgrp</STRONG> is set, then it is used with two
+ arguments, the column number of the left and right margins, in that
+ order.
+
+ <STRONG>o</STRONG> Likewise, if only one of <STRONG>smgtp</STRONG> and <STRONG>smgbp</STRONG> is set, then it is used
+ with two arguments that give the top and bottom margins, in that
+ order, counting from the top of the page.
+
+ When designing a terminfo entry for a printer that requires setting
+ both left and right or top and bottom margins simultaneously, only
+ one capability in the pairs <STRONG>smglp</STRONG> and <STRONG>smgrp</STRONG> or <STRONG>smgtp</STRONG> and <STRONG>smgbp</STRONG>
+ should be defined, leaving the other unset.
+
+ Except for very old terminal descriptions, e.g., those developed for
+ SVr4, the scheme just described should be considered obsolete. An
+ improved set of capabilities was added late in the SVr4 releases (<STRONG>smglr</STRONG>
+ and <STRONG>smgtb</STRONG>), which explicitly use two parameters for setting the
+ left/right or top/bottom margins.
+
+ When setting margins, the line- and column-values are zero-based.
+
+ The <STRONG>mgc</STRONG> string capability should be defined. Applications such as
+ <STRONG><A HREF="tabs.1.html">tabs(1)</A></STRONG> rely upon this to reset all margins.